### Abstract

We study the effect of the Fermi surface anisotropy on the odd-frequency spin-triplet pairing component of the induced pair potential. We consider a superconductor/ ferromagnetic insulator (S/FI) hybrid structure formed on the 3D topological insulator (TI) surface. In this case three ingredients ensure the possibility of the odd-frequency pairing: (1) the topological surface states, (2) the induced pair potential, and (3) the magnetic moment of a nearby ferromagnetic insulator. We take into account the strong anisotropy of the Dirac point in topological insulators when the chemical potential lies well above the Dirac cone and its constant energy contour has a snowflake shape. Within this model, we propose that the S/FI boundary should be properly aligned with respect to the snowflake constant energy contour to have an odd-frequency symmetry of the corresponding pairing component and to insure the Majorana bound state at the S/FI boundary. For arbitrary orientation of the boundary, the Majorana bound state is absent. This provides a selection rule to the realization of Majorana modes in S/FI hybrid structures, formed on the topological insulator surface.

Original language | English |
---|---|

Article number | 295502 |

Journal | Journal of Physics Condensed Matter |

Volume | 29 |

Issue number | 29 |

DOIs | |

Publication status | Published - 19 Jun 2017 |

Externally published | Yes |

### Fingerprint

### Keywords

- Majorana fermion
- odd-frequency pairing
- proximity effect
- topological insulators

### ASJC Scopus subject areas

- Materials Science(all)
- Condensed Matter Physics

### Cite this

*Journal of Physics Condensed Matter*,

*29*(29), [295502]. https://doi.org/10.1088/1361-648X/aa75c3

**Odd-frequency superconductivity induced in topological insulators with and without hexagonal warping.** / Vasenko, A. S.; Golubov, A. A.; Silkin, V. M.; Chulkov, E. V.

Research output: Contribution to journal › Article

*Journal of Physics Condensed Matter*, vol. 29, no. 29, 295502. https://doi.org/10.1088/1361-648X/aa75c3

}

TY - JOUR

T1 - Odd-frequency superconductivity induced in topological insulators with and without hexagonal warping

AU - Vasenko, A. S.

AU - Golubov, A. A.

AU - Silkin, V. M.

AU - Chulkov, E. V.

PY - 2017/6/19

Y1 - 2017/6/19

N2 - We study the effect of the Fermi surface anisotropy on the odd-frequency spin-triplet pairing component of the induced pair potential. We consider a superconductor/ ferromagnetic insulator (S/FI) hybrid structure formed on the 3D topological insulator (TI) surface. In this case three ingredients ensure the possibility of the odd-frequency pairing: (1) the topological surface states, (2) the induced pair potential, and (3) the magnetic moment of a nearby ferromagnetic insulator. We take into account the strong anisotropy of the Dirac point in topological insulators when the chemical potential lies well above the Dirac cone and its constant energy contour has a snowflake shape. Within this model, we propose that the S/FI boundary should be properly aligned with respect to the snowflake constant energy contour to have an odd-frequency symmetry of the corresponding pairing component and to insure the Majorana bound state at the S/FI boundary. For arbitrary orientation of the boundary, the Majorana bound state is absent. This provides a selection rule to the realization of Majorana modes in S/FI hybrid structures, formed on the topological insulator surface.

AB - We study the effect of the Fermi surface anisotropy on the odd-frequency spin-triplet pairing component of the induced pair potential. We consider a superconductor/ ferromagnetic insulator (S/FI) hybrid structure formed on the 3D topological insulator (TI) surface. In this case three ingredients ensure the possibility of the odd-frequency pairing: (1) the topological surface states, (2) the induced pair potential, and (3) the magnetic moment of a nearby ferromagnetic insulator. We take into account the strong anisotropy of the Dirac point in topological insulators when the chemical potential lies well above the Dirac cone and its constant energy contour has a snowflake shape. Within this model, we propose that the S/FI boundary should be properly aligned with respect to the snowflake constant energy contour to have an odd-frequency symmetry of the corresponding pairing component and to insure the Majorana bound state at the S/FI boundary. For arbitrary orientation of the boundary, the Majorana bound state is absent. This provides a selection rule to the realization of Majorana modes in S/FI hybrid structures, formed on the topological insulator surface.

KW - Majorana fermion

KW - odd-frequency pairing

KW - proximity effect

KW - topological insulators

UR - http://www.scopus.com/inward/record.url?scp=85021150708&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85021150708&partnerID=8YFLogxK

U2 - 10.1088/1361-648X/aa75c3

DO - 10.1088/1361-648X/aa75c3

M3 - Article

VL - 29

JO - Journal of Physics Condensed Matter

JF - Journal of Physics Condensed Matter

SN - 0953-8984

IS - 29

M1 - 295502

ER -